Re: [PATCH] USB: Always map transfer_buffer (Fixes some musb_hdrc issues)
Alan Stern <[email protected]>
| Newsgroups | gmane.linux.usb.devel |
|---|---|
| Message-ID | <[email protected]> |
On Wed, 28 Mar 2007, Tony Lindgren wrote: > Hi, > > Here's a little patch to make sure tranfer_buffer is always if DMA > is temporarily unavailable. I ran into this with tusb6010 that > currently can only do limited DMA. This fixes a problem of connecting > storage devices and doing mixed DMA/PIO access. Your patch isn't correct, or at least, it is very misleading. It calls page_address() in a situation where it cannot be certain that the page frame lies in accessible kernel memory. On some systems the value it calculates will be garbage. At a minimum you need to add a comment explaining that if the page isn't accessible, the transfer_buffer value won't ever be used. Alan Stern ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel